The present invention relates to a magnetic head carriage device for a magnetic disk drive apparatus.
In recent years, portable word processers and personal computers are becoming more compact (particularly, thinner). Because of this, magnetic disk drive apparatuses to be incorporated in these word processers and computers are required to be thinner. FIG. 1 shows a magnetic head carriage device 10 according to the prior arts. The magnetic head carriage device has a construction in which a bearing metal 14 is fixedly inserted into an accommodation 13a for the bearing metal, the accommodation being attached to a body 13 of the magnetic head carriage device made of synthetic resin to which a lower magnetic head 12 is provided. The magnetic head carriage device also includes an upper arm 15 and an upper magnetic head 16.
FIG. 2 and FIG. 3 show a cartridge magnetic disk drive apparatus 20 in which the above-mentioned magnetic head carriage device 10 is incorporated. A cartridge 22, in which a magnetic disk 21 is accommodated, is inserted into a cartridge holder 23 as shown by an arrow C and held thereto in a predetermined loading position. In this arrangement, the magnetic disk is rotated by a motor (not shown) and the magnetic head carriage device 10 is moved in two directions as shown by arrows A and B (radial direction of the magnetic disk 21) with the guidance of a guiding shaft 24, thereby the recording and reproducing of information being performed.
The accommodation 13a for the bearing metal should have a certain extent of strength so that it can fixedly receive the bearing metal 14. The portion of the accommodation peripheral to an inserted metal has a relatively large thickness t.sub.1, which is in the range of 0.6-1.0 mm.
Because of this, in the magnetic head carriage device 10, the height h.sub.1 between a head surface of the magnetic disk 12 and the lower surface thereof is relatively large, which is approximately 4.5 mm.
This also makes the height h.sub.2 of the magnetic head carriage device 10 relatively large, which is approximately 16 mm.
Further, in the magnetic disk drive apparatus 20, there is provided a apparatus body 25 which is made through a die casting process, the chassis base 25a must have a predetermined thickness t.sub.2 to ensure a certain strength.
Because of this, in the magnetic disk drive apparatus 20 locating the above-mentioned magnetic head carriage device 10 on the chassis base 25a, the height h.sub.3 between the magnetic head 12 and the bottom surface and hence the overall height h.sub.4 of the apparatus has been made large.